Castrum/Praetorium stories are amazing if you get to experience them properly. I tried my best to do that, asking a group from my FC to do it with me, so I got to watch the cutscenes - until we got hit with massive server disconnect issues throughout our Praetorium run and I missed a lot of it, including the epic finale after you defeat the last boss.

(Interestingly, when I went to the inn afterwards to see what I'd missed, the only cutscenes available were the ones I'd been present for - eg. if I'd disconnected halfway through a fight and re-entered the game after it finished, I would not have that post-fight cutscene included in the viewer. I didn't know what I was missing until I played it a second time through the roulette and 'discovered' all the extra scenes. I wonder if you'd have the same issue as a new player being so far behind the group that you don't get to participate in the battles - does that prevent you from seeing the cutscene afterwards?)

Re-designing at least the Praetorium for solo play would be wonderful - perhaps with some of the Scions as NPC companions? (I forget who is available at that point - did the story deliberately send everyone else to other missions so they're 'not available to help you'?) Still keep the party version as well, so you can choose whether to experience it solo or with a group.